diff options
Diffstat (limited to 'arch/x86/include/asm/pgtable-3level.h')
| -rw-r--r-- | arch/x86/include/asm/pgtable-3level.h | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h index bc4af5453802..f24df59c40b2 100644 --- a/arch/x86/include/asm/pgtable-3level.h +++ b/arch/x86/include/asm/pgtable-3level.h @@ -158,7 +158,6 @@ static inline pte_t native_ptep_get_and_clear(pte_t *ptep) #define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp) #endif -#ifdef CONFIG_SMP union split_pmd { struct { u32 pmd_low; @@ -166,6 +165,8 @@ union split_pmd { }; pmd_t pmd; }; + +#ifdef CONFIG_SMP static inline pmd_t native_pmdp_get_and_clear(pmd_t *pmdp) { union split_pmd res, *orig = (union split_pmd *)pmdp; @@ -181,6 +182,40 @@ static inline pmd_t native_pmdp_get_and_clear(pmd_t *pmdp) #define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp) #endif +#ifndef pmdp_establish +#define pmdp_establish pmdp_establish +static inline pmd_t pmdp_establish(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp, pmd_t pmd) +{ + pmd_t old; + + /* + * If pmd has present bit cleared we can get away without expensive + * cmpxchg64: we can update pmdp half-by-half without racing with + * anybody. + */ + if (!(pmd_val(pmd) & _PAGE_PRESENT)) { + union split_pmd old, new, *ptr; + + ptr = (union split_pmd *)pmdp; + + new.pmd = pmd; + + /* xchg acts as a barrier before setting of the high bits */ + old.pmd_low = xchg(&ptr->pmd_low, new.pmd_low); + old.pmd_high = ptr->pmd_high; + ptr->pmd_high = new.pmd_high; + return old.pmd; + } + + do { + old = *pmdp; + } while (cmpxchg64(&pmdp->pmd, old.pmd, pmd.pmd) != old.pmd); + + return old; +} +#endif + #ifdef CONFIG_SMP union split_pud { struct { |